Bio-interface engineering of MXene nanosheets with immobilized lysozyme for light-enhanced enzymatic inactivation of methicillin-resistant Staphylococcus aureus

Being a unique biocatalyst to hydrolyse structural polysaccharides on the cell wall of bacteria, lysozyme can slow down bacterial resistance caused by antibiotic overdose treatments, however, efficient activation of lysozyme activities under pathogenic microenvironments remains challenging. Herein, a bio-interface engineering strategy was proposed for the remote modulation of thermoresistant lysozyme upon rationally designed photothermal nanoplatforms. For this, Ti3C2TX MXene nanosheets were functionalized by polydopamine (PDA) surface chemistry to enhance photothermal effects and performance durability, during which lysozyme bio-macromolecules were immobilized at such a two-dimensional hybrid interface via intermolecular electrostatic affinity. The integrated nanoplatform (denoted as M@P@Lyso), with an optimal high light-to-heat conversion efficiency of 46.88%, realized not only precision control of local heat but also photo-responsive up-regulation for bio-catalysis of laden lysozyme. As a result, in vitro and in vivo antibacterial experiments revealed that M@P@Lyso could effectively inhibit the proliferation of methicillin-resistant Staphylococcus aureus and accel-erated wound disinfection of mice with negligible biological toxicities. The outstanding antibacterial activities of M@P@Lyso were attributed to the photo-enhanced lysozyme activity, assisted by bacterial death caused by the mild local hyperthermia and the physical destruction derived from the M@PDA. This work exemplified a solution to the bacterial resistance threats via stimuli-responsive enzymatic nanoplatforms.

Automated summary

In this study, a bio-interface engineering strategy was proposed to remotely modulate thermoresistant lysozyme using a designed photothermal nanoplatform. The nanoplatform showed precise control of local heat and up-regulation of bio-catalytic activity. In vitro and in vivo experiments demonstrated the effective antibacterial properties of the nanoplatform with low biological toxicity.